Process of preparing iodophors of nonionic synthetic surfactants



United States Patent 3,285,816 PROCESS OF PREPARING IODOPHORS 0F NON- IONIC SYNTHETIC SURFACTANTS Harry Kaplan, Westfield, and Winfred C. Craig, West Long Branch, N.J., assignors to General Aniline & Film Corporation, New York, N.Y., a corporation of Delaware No Drawing. Filed May 23, 1963, Ser. No. 282,814 6 Claims. (Cl. 167-70) This invention relates to an improved process of preparing iodophors of non-ionicsynthetic surfactants which are stable and which have a higher ratio of available iodine to total iodine.

An iodophor is defined by Terry and Shelanski in Modern Sanitation, 4,.pp. 6165, January 1952, as a mixture of iodine and a carrier in which the carrier is a compound that greatly increases the solubility of and tends to stabilize iodine in aqueous systems to reactants other than microorganisms. In American Perfumer for May 1961, page 44, Connor notes that such carriers may include anionic, cationic, or polymeric type material as well as non-ionic surfactants; the objective generally is to produce a detergent sanitizer. As pointed out by Raphael in Manufacturing Chemist for December 1961, and as is suggested in the existing patent literature, it is desirable to have in the iodiphors as high a concentration of iodine as possible.

In the manufacture of an iodophor, as generally practiced, the carrier system is heated to 40 to 80 C. With agitation the system is maintained on temperature and then there is added elemental iodine in an amount equivalent to 10 to 40% of the weight of carrier. After all the iodine has been added, the reaction mixture is kept on temperature with continued agitation for from one-quarter hour to six hours additional. The total iodine in the system is determined by the Volhard method, after reduction to iodide; the available iodine is measured iodometrically by a .thiosulfate tritration.

Iodophors made from non-ionic synthetic surfactants are characterized by a serious economic disadvantage in that only some 75-80% of the iodine employed in such manufacture is useful, the remainder of the iodine being bound up in the product in some form in which it cannot be utilized for sanitation applications. In other words, not all the iodine employed in the manufacture of the iodophor is available for germicidal use regardless of the total concentration of iodine in the carrier. As one approaches the upper limits of solubility of iodine in the carrier, as much as 25% of the iodine total may be present in such a way as to be not available for the desired germicidal activity. Moreover, such iodophors are not stable and lose available iodine after long periods of storage at room temperature or at moderately elevated temperature, i.e., C. to C.

Accordingly, it is the principal object of the present invention to provide a process of preparing iodophors of non-ionic synthetic surfactants in which the ratio of germicidally available iodine to total iodine (employed in iodophor preparation) is substantially greater than has been heretofore obtainable.

Other objects and advantages will be more clearly manifest from the following description.

We have found that the foregoing objects are readily" The non-ionic synthetic surfactants characterized by the first general formula are normally prepared by the usual methods known to the art by the condensation of 1 mole of either an alkyl alcohol of from 6-27 carbon atoms, an aryl alcohol of from 6 to 24 carbon atoms or alkyl aryl alcohol of from 7-24 carbon atoms with 6-100 moles of ethylene oxide, propylene oxide or butylene oxide. More specifically, R represents an alkyl radical containing from 6 to 27 carbon atoms, e.g., hexyl, octyl, nonyl, decyl, hendecyl, dinonyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, eicosyl, heneicosyl, docosyl, tricosyl, tetracosyl, pentacosyl, hexacosyl, and heptacosyl, or an aryl radical of 6 to 24 carbon atoms, e.g., phenyl, diphneyl, naphthyl, etc. which are unsubstituted or substituted by an alkyl radical of from 1 to 18 carbon atoms, e.g., dimethylphenyl, dipropylphenyl, nonylphenyl, dinonylphenyl, octadecylphenyl, etc., R represents either hydrogen, methyl, group or ethyl group and n represents an integer of from 6 to 100.

Suitable methods for the preparation of the non-ionic synthetic surfactants characterized by the first formula are described in United States Patents 1,970,578; 2,213,- 477; 2,575,832; 2,593,112; 2,676,975; 2,759,869 and 2,931,777, the complete disclosures and teaching of which are incorporated herein by reference thereto.

The non-ionic synthetic surfactants which are characterized by Formula 2, wherein y equals at least 15 and (C H O) equals 20 to of the total weight of said compound, are more fully disclosed in United States Patents Nos. 2,674,619 and 2,759,869, the complete disclosures and teachings of which are likewise incorporated herein by reference thereto. These non-ionics are generally referred to as Pluronics and are commercially available through sales distributors of the Wyandotte Chemicals Corporation. They are available under the trade and code names having the following chemical compositions:

Pluronic L-62=25 to 30 moles of polyoxypropylene condensed with 8.5 to 10.2 moles of ethylene oxide Pluronic P 65=25 to 30 moles of polyoxypropylene condensed with 50 to 60 moles of ethylene oxide Pluronic F68=25 to 30 moles of polyoxypropylene condensed with 33 to 41 moles of ethylene oxide Pluronic P84=36 to 43 moles of po-lyoxypropylene condensed with 40 to 50 moles of ethylene oxide Pluronic P85=36 to 43 moles of polyoxypropylene condensed with 48 to 52 moles of ethylene oxide With reference to Formula 2, we prefer to use those Pluroni-cs wherein the group (C H O) has a molecular weight of at least 1500.

The halogenation may be either chlorination or bromination. In the first instance this is accomplished by bubbling chlorine gas into the liquid non-ionic synthetic surfactant at a temperature of from ambient to C. until not less than 2% and not more than 4% of chlorine, based on the weight of the non-ionic, has been bound in the product. The non-ionic synthetic surfactants which are solids at ordinary temperatures are rendered liquid by melting and maintained in the liquid form during the chlorination reaction.

The reaction mixture is agitated While passing in the .chlorine by bubbling and is maintained at the aforementioned temperature for a period of time sulficient to cause the chlorine to react at a suitable rate. The time may vary from twenty minutes to two and a half hours. In this connection it is to be noted that the higher the temperature the shorter the time of chlorination. The

total chlorine is determined by the conventional Parr combustion method and if desired the inorganic chlorine may be determined by the Volhard method, iodometric titration with sodium thiosulfate.

The bromination is simply accomplished by incremental addition of liquid bromine to the liquid non-ionic, i.e., slightly above its melting point if it be a solid, until not less than and not more than 8% of total bromine, based on the weight of the non-ionic, has been bound in the product. The total bromine is determined by the conventional Parr combustion method and the inorganic bromine if desired may be determined by the' Volhard method.

During the course of experimentation with the present invention we have found that the foregoing percentage ratio of chlorine or bromine is about stoichiometr-ically equivalent to the amount of iodine that is normally bound in the iodophor in non-useful form. In other words, the relatively inexpensive bound chlorine or brominereplaces the more expensive iodine.

It is to be understood that, while a single non-ionic synthetic surfactant of one of the above general formulae is preferred as the iodophor base, a mixture of one or more non-ionics characterized by Formula 1 and/ or Formula 2 may likewise be used. 7

After the halogenation step has been completed, the aforedescribed iodophor manufacturing procedure is employed. After the iodine has all been added, i.e., from 10 to 40% by weight of the halogenated non-ionic, the system is maintained on temperature (i.e. 40 to 80 C.) with continued agitation to insure complete 'solubilization.

The following examples will illustrate the practice of the present invention. All parts given are by weight unless otherwise noted.

Example 1a To a 500 cc. round-bottom reaction flask fitted with thermometer, agitator, and condenser, and equipped with a heating mantle, there is charged 216 parts of a nonionic obtained by condensing one mole of nonylphenol To a reaction flask, as in Example 1a and fitted additionally with a gas inlet tube, is charged 226 parts of the non-ionic consisting of the condensate of 1 mole of nonylphenol with 9 moles of ethylene oxide. The mass is agitated and heated to 70 C. and into it is bubbled 14 parts of chlorine over a period of 20 minutes.

Analysis: Percent Total chlorine 2.7 Inorganic chlorine 0.07

Cloud point 44 C. as against 59 C. for starting non-ionic sufactants.

To the chlorinated product there is then added 66 parts of finely ground iodine. As in Example 1a, the reaction mixture is maintained at 68 C. with agitation for three hours after total iodine addition, and the reb was derived from carrier a by chlorination.

action product is then discharged and analyzed.

Analysis Percent Total iodine 22.0 Available iodine 19.5 Available/total 88.5

The following table shows the results of additional experiments in accordance with Examples 1a and lb. The non-ionic carriers for iodophors consisted of condensation products of phenol and various alkylated phenols with ethylene oxide. The designation dodecylphenol+8 E.O. means that 1 mole of dodecylphenol was condensed with 8 moles of ethylene oxide in the usual manner. Carrier In each of the examples listed in the table, carn'er b contained approximately 3.0% of total chlorine. All parts are by with 9 moles of ethylene oxide. The contents of the welght.

Avail- Non-ionic Carrier for Parts .Available Example Iodophor Parts Iodine able Iodine as Iodine percent of tota DodecylphenOH-S E.O 72.0 28 .0 21.3 76

Diisobutylphenol-l-Z E.O 72 .0 28.0 20.7 74

78.0 22.0 21.0 95.4 Phenol-l-fi E.O 72 .0 28 .0 21 .9 78 .3 78.0 22.0 19.2 87.3 Butylphenol+12 E .O 72 .0 28 .0 22 .0 78 .5 78 .0 22 .0 19 .9 .6 Nonylphen0l+150 E.O 72 .0 28 .0 21.6 77 .3 78 .0 22.0 20 .6 93 .0 Dodecy1phen0l+150 E.O 72 .0 28 .0 21.4 76 .6 78.0 22.0 21.1 96.0 Nonylphen0l+30 E .O 72 .0 28 .0 22 .2 79 .3 78 .0 22 .0 20 .8 94.5 Dodecylphenol+20 E.O 90 .0 1 0.0 8 .4 84.0 92 .0 8 .0 7 .8 97 .5 Nonylphen0l+20 E.O 90 .0 10 .0 8 .6 86 .0 92 .0 8 .0 7 .7 96 .3 Dinonylphenol+40 E.O 84 .0 16 .0 12 .4 77 .5 88.0 12.0 11.5 96.0 Didecylphenol+30 E.O 79 .0 21.0 16 .6 79 .0 84.0 16.0 15.4 96.3 1311 Dioctylphenol+10 E.O 76.0 24.0 17.5 73.0 13b 76.0 24.0 22.6 94.0 14a Nonylphenol+9 E.O 71.0 29 .0 21 .4 73 .8 1%.. 71.0 29.0 27.5 94.8 15a Dinonylphenol+15 E.O 70.0 30.0 24.8 82.5 15b 70.0 30.0 28.2 94.0

Example I 6 reaction flask are heated to 68 C. with agitation and then there is added gradually 84 parts of finely ground iodine. The reaction mixture is maintained at 68 C. with agitation for three hours after all the iodine is added, the product is discharged and analyzed.

following exceptions.

After all the bromine was added, the system was agitated, heated to 50 C. and held on temperature 3 hours additional. To the brominated product, which upon analysis showed 7.1% of total bromine, there was then added 66 parts finely ground iodine; the reaction mixure was maintained at 72 C. with agitation for 4 hours, and the product was discharged and analyzed.

Analysis:

Percent Total iodine 18.8 Available iodine 18.0 Available/total 95.3

All b products of the foregoing examples were subjected to storage tests for three (3) months at room temperature and in an electrically controlled oven at 35 C. All of them were stable and did not show any loss of available iodine.

From the foregoing examples it is clearly evident that the preparation of stable non-ionic idophor in accordance with the present invention reduces considerably the amount of total iodine employed in such preparation, while at the same time making the available iodine remain at the desired high level. In other words, the highly desirable advantage of the invention is the great economy in achieving the desired high level of available iodine while utilizing a relatively lower total iodine concentration.

The nature or character of the non-ionic synthetic surfactant that may be employed in the process of the present invention is immaterial so long as it is watersoluble or capable of solubility in water in its salt form such as sulfonate or sulfate, preferably as the alkali metal of such water-solubilizing groups. The non-ionic phosphate esters of the Formulae l to 3 disclosed in U.S.P. 3,061,506 are particularly adaptable to the present invention to yield iodine phosphate ester compositions in which the ratio of available iodine to total iodine is much higher than that obtainable by converting the phosphate ester directly to iodophors. Similarly, cationics of the type disclosed in U.S.P. 2,775,604; 2,759,975; 2,876,263 may be employed for halogenation and subsequent iodophor formation.

We claim:

1. In the process of preparing a non-ionic iodophor by heating a non-ionic synthetic surfactant with to 40% by weight thereof of elemental iodine at a temperature range of 40 to 80 C., the improvement of obtaining said iodophor in stable form and having a higher ratio of available iodine to total iodine employed in said preparation which comprises first halogenating a nonionic synthetic surfactant selected from the group consisting of those of the general formulae:

wherein R represents a member selected from the class consisting of alkyl radicals of 6 to 27 carbon atoms and aryl radicals of 6 to 24 carbon atoms, R represents a member selected from the class consisting of hydrogen, methyl and ethyl, n represents an integer of from 6 to 100, y represents an integer of at least and x-l-x represents to 90% of the total weight of said nonionic, with 2 to 8% by weight thereof of a halogen selected from the class consisting of bromine and chlorine at a temperature ranging from ambient to 120 C., and then heating the halogenated surfactant with the said weight of elemental iodine within said temperature range.

2. In the process of preparing a non-ionic iodophor by heating a non-ionic synthetic surfactant with 10 to by weight thereof of elemental iodine at a temperature range of 40 to 80 C., the improvement of obtaining said iodophor in stable form and having a higher ratio 5 of available iodine to total iodine employed in said preparation which comprises first halogenating a non-ionic synthetic surfactant having the following general formula:

wherein R represents a member selected from the class consisting of alkyl radicals of from 6 to 27 carbon atoms and aryl radicals of 6 to 24 carbon atoms, R represents a member selected from the class consisting of hydrogen, methyl and ethyl, and n represents an integer of from 6 to 100, with a halogen selected from the class consisting of bromine and chlorine at a temperature ranging from ambient to 120 C., and then heating the halogenated surfactant with the said weight of elemental iodine 20 within said temperature range.

3. In the process of preparing a non-ionic iodophor by heating a non-ionic synthetic surfactant with 10 to 40% by weight thereof of elemental iodine at a temperature range of 40 to 80 C., the improvement of obtaining said iodophor in stable form and having a higher ratio of available iodine to total iodine employed in said preparation which comprises first halogenating a nonionic synthetic surfactant having the following general formula:

wherein y represents an integer of at least 15 and x-I-x' represent from 20 to 90% of the total weight of said nonionic, to a content of 2 to 8% by weight thereof of a halogen selected from the class consisting of bromine and chlorine at a temperature ranging from ambient to 120 C., and then heating the halogenated surfactant with the said weight of elemental iodine within said temperature range.

4. In the process of claim 1 wherein the non-ionic synthetic surfactant has the following formula:

Q-otornornop-n C n u 5. In the process of claim 1 wherein the non-ionic synthetic surfactant has the following formula:

C gHrn 6. In the process of claim 1 wherein the non-ionic synthetic surfactant has the following formula:

OTHER REFERENCES Deming: Fundamental Chemistry, second edition, pp. 217 and 239, 1947.

JULIAN S. LEVITI, Primary Examiner.

L. B. RANDALL, Assistant Examiner. 

1. IN THE PROCESS OF PREPARING A NON-IONIC IODOPHOR BY HEATING A NON-IONIC SYNTHETIC SURFACTANT WITH 10 TO 40% BY WEIGHT THEREOF OF ELEMENT IODINE AT A TEMPERATURE RANGE OF 40* TO 80*C., THE IMPROVEMENT OF OBTAINING SAID IODOPHOR IN STABLE FORM AND HAVING A HIGHER RATIO OF AVAILABLE IODINE TO TOTAL IODINE EMPLOYED IN SAID PREPARATION WHICH COMPRISES FIRST HALOGENATING A NONIONIC SYNTHETIC SURFACTANT SELECTED FROM THE GROUP CONSISTING OF THOSE OF THE GENERAL FORMULAE: 